Neural correlates of written emotion word processing: A review of recent electrophysiological and hemodynamic neuroimaging studies

Abstract

A growing body of literature investigating the neural correlates of emotion word processing has emerged in recent years. Written words have been shown to represent a suitable means to study emotion processing and most importantly to address the distinct and interactive contributions of the two dimensions of emotion: valence and arousal. The aim of the present review is to integrate findings from electrophysiological (ERP) and hemodynamic neuroimaging (fMRI) studies in order to provide a better understanding of emotion word processing. It provides an up-to-date review of recent ERP studies since the review by Kissler et al. (2006) as well as the first review of hemodynamic brain imaging studies in the field. A discussion of theoretical and methodological issues is also presented, along with suggestions for future research.

Neural modulation of directed forgetting by valence and arousal: An event-related potential study

“…As predicted, the LPC showed more positivity in response to negative items at both levels of arousal. That the LPC was more sensitive to fluctuations in valence despite arousal levels also falls in line with literature suggesting that valence exerts its greatest impact during later explicit stages of information processing (i.e., 400-1000 ms post-stimulus presentation; Bayer et al, 2010;Citron, 2012).…”

“…Electrical brain activity associated with words and cues presented during encoding were separately analyzed. During word processing, the LPC was the component of interest as our primary focus was in the intentional processing of these words (Brown et al, 2012;Citron, 2012). Consistent with the literature, a greater LPC over centro-parietal and parietal electrodes was expected to emerge for words high in valence, despite arousal levels (e.g., Bayer et al, 2010;Olofsson et al, 2008;Recio et al, 2014).…”

“…Moreover, whereas emotional valence of the target word did not impact frontal-based activity in response to cues (similar to Brandt et al, 2013), each dimension differentially influenced how the brain dealt with instructions to remember and forget over parietal sites. The interesting activation patterns we observed for positive high and negative low arousing words seem to be best explained by conflicting approach-withdrawal reactions that required greater processing to resolve (Citron, 2012;Robinson, 1998). All in all, and perhaps most importantly, the findings support a multidimensional model of emotion that should be taken into account during experimentation.…”

“…The authors argued this reflected sustained attention toward those items, which may be rooted in conflicting approach-withdrawal reactions toward positive high and negative low arousing words. This draws on motivational theories suggesting that items with either positive valence or low arousal evoke an approach-orientation as they are presumed to be "safe", whereas negative valence or high arousal items elicit a withdrawalorientation as they induce a feeling of "threat" (Citron, 2012;Robinson, 1998). Citron et al (2013) argue that when a conflict is created between the approach-withdrawal orientations, such as with high arousal positive and low arousal negative items, increased cognitive resources are required by the brain to deal with the conflict.…”

“…fMRI studies have shown that processing of valence and arousal are supported by distinct brain networks (Kensinger & Corkin, 2004) and have varying temporal representations (Bayer, Sommer, & Schacht, 2010;Citron, Weekes, & Ferstl, 2013;Olofsson, Nordin, Sequeira, & Polich, 2008;Recio, Conrad, Hansen, & Jacobs, 2014). In the ERP literature, two prominent components associated with emotional word processing include the early posterior negativity (EPN) and the LPC (for reviews see Citron, 2012, and, Olofsson et al, 2008. Specifically, greater negative deflections have been found in response to words high in arousal during early time windows, typically 200-350 ms post onset of the word (i.e., the EPN).…”